“How long does local anesthesia last for hand surgery?”

If your hand surgery is minor and you get an IV regional, then as soon as the tourniquet is released, the arm gets the feelings back. If it is long complex surgery and if brachial plexus block is given, then the length of the block will depend on the type of drug used, from 2-3 hrs to may be 24 hrs.

Depends on local anesthetic used. Can be 10+ hours.

There is no easy answer for this question, as the duration of effect depends on multiple factors. There are a few different medications which can be injected to provide local anesthesia or a regional nerve block. Additionally, there are "additives" that can be mixed in with the local anesthesia prior to injection, such as epinephrine, that prolong the duration of anesthesia. Additionally it depends to some extent on exactly how the injection is made, such as whether it is just injected under the skin to provide local anesthesia or if it is injected around a nerve bundle to provide a regional block. Finally, it depends on the patient's blood flow and clearance mechanisms that are somewhat unique to each individual. These mechanisms determine the speed at which the deposited bolus on anesthetic is either metabolized (broken down), removed from the site in which it was deposited, and ultimately removed from the body.

About one to two hours.